Rheology modified low foaming liquid antimicrobial compositions and methods of use thereof

ABSTRACT

The present disclosure relates to rheology modified, low foaming aqueous antimicrobial compositions. The compositions are phase stable under acidic conditions, and do not need to be rinsed from the surface to which they are applied. The present disclosure further relates to methods of use thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/736,311, filed Jan. 7, 2020, which is a Divisional of U.S.application Ser. No. 13/112,624, filed May 20, 2011, which claimspriority to U.S. Provisional Application Ser. No. 61/346,804, filed May20, 2010, entitled “Rheology Modified Low Foaming Liquid AntimicrobialCompositions and Methods of Use Thereof” The entire contents of thesepatent applications are hereby expressly incorporated herein byreference including, without limitation, the specification, claims, andabstract, as well as any figures, tables, or drawings thereof.

FIELD

The present disclosure relates to aqueous low foaming antimicrobialcompositions, and methods of use thereof.

BACKGROUND

During processing, preparation, packaging and serving, food products mayencounter microorganisms that may make the food unsuitable forconsumption. The microorganisms may come from the food itself, foodcontact surfaces, and/or the surrounding environment. The microorganismscan range from pathogenic microorganisms (e.g., Listeria monocytogenes,enterohemorrhagic Escherichia coli, Salmonella and the like) to spoilageorganisms that can affect the taste, color, and/or smell of the finalfood product (e.g. Pseudomonas spp, Erwinia carotovora, Fusarium spp andthe like). Microorganisms can affect a wide variety of food productsincluding meat, poultry, fish and shellfish, cheese, fruits andvegetables, and pre-prepared foods. At certain levels, the presence ofmicroorganisms on a food product may cause everything from a consumer'sperception of a lower quality product, to regulatory investigations andsanctions, to food borne illness or death.

Food processors, grocery retailers, full service restaurants (FSR) andquick service restaurants (QSR) use a variety of methods to treat foodproducts during processing to reduce the presence of microorganisms onfood products. These methods include cleaning and sanitizing the foodprocessing plant and food handling environment, applying orincorporating antimicrobials to or in the food product, irradiating thefood product, applying heat, and others. Applying or incorporating anantimicrobial composition to the food product, or to the water used inwashing or transporting the food product, is a preferred way of reducingmicroorganisms. However, it is difficult to formulate a composition thatis effective at reducing microorganisms using ingredients that areacceptable for direct food contact according to government regulations.Further, it is difficult to formulate a composition that can be applieddirectly to a food product without adversely affecting the color, taste,or smell of the food product. Finally, many antimicrobials used in thetreatment of food products in the retail grocery, FSR and QSR marketsmay have worker safety concerns, material compatibility (corrosion)concerns or must be generated onsite requiring more costly equipment todispense and use the antimicrobial.

BRIEF SUMMARY OF THE INVENTION

In some aspects, the present disclosure relates to single phase aqueouslow foaming antimicrobial concentrate compositions. The compositionscomprise at least about 25 wt % water; an antimicrobial agent comprisingan anionic surfactant; a defoaming agent; an acidulant; a stabilizingagent; and a thickening agent. The compositions have a viscosity ofbetween about 50 centipoise and about 3500 centipoise, and thethickening agent is present in an amount effective such that thecomposition is phase stable under acidic conditions.

In some embodiments, the anionic surfactant is selected from the groupconsisting of alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates,sulfonated fatty acids, sulfonated fatty acid esters, sulfonatedcarboxylic acid esters, and mixtures thereof. In other embodiments, thecomposition is substantially free of a C5 to C11 carboxylic acid, achlorite, and an oxidizing agent, and mixtures thereof.

In some embodiments, the defoaming agent comprises a silicone defoamingagent. In other embodiments, the thickening agent is selected from thegroup consisting of natural polysaccharide or cellulose thickeners,plant exudates, seaweed extracts, water soluble polymers, poly acrylicacid based thickeners, polyacrylamide based thickeners, inorganic claybased thickeners, and mixtures thereof.

In other embodiments, the acidulant comprises a food additiveingredient. In still yet other embodiments, the acidulant is selectedfrom the group consisting of citric acid, sodium bisulfate, acetic acid,adipic acid, tartaric acid, propionic acid, malic acid, lactic acid,sulfuric acid, and derivatives and mixtures thereof. In someembodiments, the composition comprises: between about 0.01 wt % andabout 50 wt % of the antimicrobial agent; between about 0.01 wt % andabout 10.0 wt % defoaming agent; between about 0.1 wt % and about 10 wt% thickening agent; and between about 1 wt % to about 50 wt % of theacidulant.

In some embodiments, the composition has a pH of less than 3.2. In otherembodiments, the composition further comprises an additional ingredientselected from the group consisting of a surfactant, a processing aid, adye, a colorant, an odorant, and mixtures thereof. In still yet otherembodiments, the composition comprises between about 0.1 wt % and about5.0 wt % stabilizing agent.

In other embodiments, the stabilizing agent is present at an amounteffect to prevent the formation of a precipitate for at least 24 hourswhen the composition is diluted with 500 ppm hard water. In still yetother embodiments, the stabilizing agent comprises a block copolymer ofethylene oxide and propylene oxide. In other embodiments, the copolymershave a molecular weight of about 5,000 to about 10,000 and thepercentage of ethylene oxide is between about 70 to about 90.

In some aspects, the present disclosure relates to methods for reducinga population of microorganisms on a surface. The methods compriseproviding a single phase aqueous low foaming antimicrobial concentratecomposition. The composition comprises at least about 25 wt % water; anantimicrobial agent comprising an anionic surfactant; a defoaming agent;an acidulant selected from the group consisting of sulfates, sulfonates,and combinations thereof; a stabilizing agent; and a thickening agent.The composition has a viscosity of between about 50 centipoise and about3500 centipoise, and the thickening agent is present in an amounteffective such that the composition is phase stable under acidicconditions. The method further comprises diluting the composition; andcontacting the surface with the diluted composition such that thepopulation of microorganisms is reduced, wherein the composition doesnot need to be rinsed from the surface.

In some aspects, the present disclosure relates to methods for washingproduce. The methods comprise contacting the produce with a phase stableaqueous acidic antimicrobial composition comprising at least about 25 wt% water; an antimicrobial agent comprising an anionic surfactant; adefoaming agent; an acidulant; a stabilizing agent; and a thickeningagent. The composition is diluted prior to contacting, and has aviscosity of between about 50 centipoise and about 3500 centipoise, andthe thickening agent is present in an amount effective such that thecomposition is phase stable under acidic conditions, and the producedoes not need to be rinsed after being contacted by the composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical depiction of liquid retention and residualchemistry carryover onto lettuce versus produce wash concentration.

DETAILED DESCRIPTION OF THE INVENTION

In some aspects, the present disclosure relates to aqueous low foamingantimicrobial compositions, and methods of use thereof. The compositionsare stable, single phase compositions that can be applied directly tofood surfaces, and food contact surfaces, without the need to be rinsed.That is, the compositions can be applied directly to a food surface,e.g., fruit or vegetable surface, cutting board, and do not need to berinsed off prior to consuming or using the surface. Further, thecompositions do not substantially alter the organoleptic properties,e.g., color, texture, odor, or taste, of a food surface that theycontact. Thus, the compositions provide a no-rinse method for cleaningfood surfaces.

Definitions

So that the invention maybe more readily understood, certain terms arefirst defined. For the following defined terms, these definitions shallbe applied, unless a different definition is given in the claims orelsewhere in this specification.

As used herein, the phrases “objectionable odor,” “offensive odor,” or“malodor,” refer to a sharp, pungent, or acrid odor or atmosphericenvironment from which a typical person withdraws if they are able to.Hedonic tone provides a measure of the degree to which an odor ispleasant or unpleasant. An “objectionable odor,” “offensive odor,” or“malodor” has an hedonic tone rating it as unpleasant as or moreunpleasant than a solution of 5 wt-% acetic acid, propionic acid,butyric acid, or mixtures thereof.

As used herein, the term “microorganism” refers to any noncellular orunicellular (including colonial) organism. Microorganisms include allprokaryotes. Microorganisms include bacteria (including cyanobacteria),spores, lichens, fungi, protozoa, virinos, viroids, viruses, phages, andsome algae. As used herein, the term “microbe” is synonymous withmicroorganism.

As used herein, the phrase “food product” includes any food substancethat might require treatment with an antimicrobial agent or compositionand that is edible with or without further preparation. Food productsinclude meat (e.g. red meat and pork), seafood, poultry, produce (e.g.,fruits and vegetables), eggs, living eggs, egg products, ready to eatfood, wheat, seeds, roots, tubers, leafs, stems, corns, flowers,sprouts, seasonings, or a combination thereof. The term “produce” refersto food products such as fruits and vegetables and plants orplant-derived materials that are typically sold uncooked and, often,unpackaged, and that can sometimes be eaten raw.

As used herein, the phrase “plant” or “plant product” includes any plantsubstance or plant-derived substance. Plant products include, but arenot limited to, seeds, nuts, nut meats, cut flowers, plants or cropsgrown or stored in a greenhouse, house plants, and the like. Plantproducts include many animal feeds.

As used herein, the phrase “meat product” refers to all forms of animalflesh, including the carcass, muscle, fat, organs, skin, bones and bodyfluids and like components that form the animal. Animal flesh includes,but is not limited to, the flesh of mammals, birds, fishes, reptiles,amphibians, snails, clams, crustaceans, other edible species such aslobster, crab, etc., or other forms of seafood. The forms of animalflesh include, for example, the whole or part of animal flesh, alone orin combination with other ingredients. Typical forms include, forexample, processed meats such as cured meats, sectioned and formedproducts, minced products, finely chopped products, ground meat andproducts including ground meat, whole products, and the like.

As used herein the term “poultry” refers to all forms of any bird kept,harvested, or domesticated for meat or eggs, and including chicken,turkey, ostrich, game hen, squab, guinea fowl, pheasant, quail, duck,goose, emu, or the like and the eggs of these birds. Poultry includeswhole, sectioned, processed, cooked or raw poultry, and encompasses allforms of poultry flesh, by-products, and side products. The flesh ofpoultry includes muscle, fat, organs, skin, bones and body fluids andlike components that form the animal. Forms of animal flesh include, forexample, the whole or part of animal flesh, alone or in combination withother ingredients. Typical forms include, for example, processed poultrymeat, such as cured poultry meat, sectioned and formed products, mincedproducts, finely chopped products and whole products.

As used herein, the phrase “poultry debris” refers to any debris,residue, material, dirt, offal, poultry part, poultry waste, poultryviscera, poultry organ, fragments or combinations of such materials, andthe like removed from a poultry carcass or portion during processing andthat enters a waste stream.

As used herein, the phrase “food processing surface” refers to a surfaceof a tool, a machine, equipment, a structure, a building, or the likethat is employed as part of a food processing, preparation, or storageactivity. Examples of food processing surfaces include surfaces of foodprocessing or preparation equipment (e.g., slicing, canning, ortransport equipment, including flumes), of food processing wares (e.g.,utensils, dishware, wash ware, and bar glasses), and of floors, walls,or fixtures of structures in which food processing occurs. Foodprocessing surfaces are found and employed in food anti-spoilage aircirculation systems, aseptic packaging sanitizing, food refrigerationand cooler cleaners and sanitizers, ware washing sanitizing, blanchercleaning and sanitizing, food packaging materials, cutting boardadditives, third-sink sanitizing, beverage chillers and warmers, meatchilling or scalding waters, autodish sanitizers, sanitizing gels,cooling towers, food processing antimicrobial garment sprays, andnon-to-low-aqueous food preparation lubricants, oils, and rinseadditives.

As used herein, the term “ware” refers to items such as eating andcooking utensils, dishes, and other hard surfaces such as showers,sinks, toilets, bathtubs, countertops, windows, mirrors, transportationvehicles, and floors. As used herein, the term “warewashing” refers towashing, cleaning, or rinsing ware. Ware also refers to items made ofplastic. Types of plastics that can be cleaned with the compositionsaccording to the invention include but are not limited to, those thatinclude polycarbonate polymers (PC), acrilonitrile-butadiene-styrenepolymers (ABS), and polysulfone polymers (PS). Another exemplary plasticthat can be cleaned using the compounds and compositions of theinvention include polyethylene terephthalate (PET).

As used herein, the phrase “air streams” includes food anti-spoilage aircirculation systems. Air streams also include air streams typicallyencountered in hospital, surgical, infirmity, birthing, mortuary, andclinical diagnosis rooms.

As used herein, the term “waters” includes food process or transportwaters. Food process or transport waters include produce transportwaters (e.g., as found in flumes, pipe transports, cutters, slicers,blanchers, retort systems, washers, misting equipment and the like),belt sprays for food transport lines, boot and hand-wash dip-pans,third-sink rinse waters, and the like. Waters also include domestic andrecreational waters such as pools, spas, recreational flumes and waterslides, fountains, and the like.

As used herein, the phrase “health care surface” refers to a surface ofan instrument, a device, a cart, a cage, furniture, a structure, abuilding, or the like that is employed as part of a health careactivity. Examples of health care surfaces include surfaces of medicalor dental instruments, of medical or dental devices, of electronicapparatus employed for monitoring patient health, and of floors, walls,or fixtures of structures in which health care occurs. Health caresurfaces are found in hospital, surgical, infirmity, birthing, mortuary,and clinical diagnosis rooms. These surfaces can be those typified as“hard surfaces” (such as walls, floors, bed-pans, etc.), or fabricsurfaces, e.g., knit, woven, and non-woven surfaces (such as surgicalgarments, draperies, bed linens, bandages, etc.,), or patient-careequipment (such as respirators, diagnostic equipment, shunts, bodyscopes, wheel chairs, beds, etc.,), or surgical and diagnosticequipment. Health care surfaces include articles and surfaces employedin animal health care.

As used herein, the term “instrument” refers to the various medical ordental instruments or devices that can benefit from cleaning with acomposition according to the present invention.

As used herein, the phrases “medical instrument,” “dental instrument,”“medical device,” “dental device,” “medical equipment,” or “dentalequipment” refer to instruments, devices, tools, appliances, apparatus,and equipment used in medicine or dentistry. Such instruments, devices,and equipment can be cold sterilized, soaked or washed and then heatsterilized, or otherwise benefit from cleaning in a composition of thepresent invention. These various instruments, devices and equipmentinclude, but are not limited to: diagnostic instruments, trays, pans,holders, racks, forceps, scissors, shears, saws (e.g., bone saws andtheir blades), hemostats, knives, chisels, rongeurs, files, nippers,drills, drill bits, rasps, burrs, spreaders, breakers, elevators,clamps, needle holders, carriers, clips, hooks, gouges, curettes,retractors, straightener, punches, extractors, scoops, keratomes,spatulas, expressors, trocars, dilators, cages, glassware, tubing,catheters, cannulas, plugs, stents, scopes (e.g., endoscopes,stethoscopes, and arthoscopes) and related equipment, and the like, orcombinations thereof.

As used herein, “agricultural” or “veterinary” objects or surfacesinclude animal feeds, animal watering stations and enclosures, animalquarters, animal veterinarian clinics (e.g., surgical or treatmentareas), animal surgical areas, and the like.

As used herein, the term “phosphorus-free” or “substantiallyphosphorus-free” refers to a composition, mixture, or ingredient thatdoes not contain phosphorus or a phosphorus-containing compound or towhich phosphorus or a phosphorus-containing compound has not been added.Should phosphorus or a phosphorus-containing compound be present throughcontamination of a phosphorus-free composition, mixture, or ingredients,the amount of phosphorus shall be less than 0.5 wt %. More preferably,the amount of phosphorus is less than 0.1 wt %, and most preferably theamount of phosphorus is less than 0.01 wt %.

For the purpose of this patent application, successful microbialreduction is achieved when the microbial populations, e.g., microbialpopulations on surfaces or in water, are reduced by at least about 50%,or by significantly more than is achieved by a wash with water. Largerreductions in microbial population provide greater levels of protection.

As used herein, the term “sanitizer” refers to an agent that reduces thenumber of bacterial contaminants to safe levels as judged by publichealth requirements. In an embodiment, sanitizers for use in thisinvention will provide at least a 99.999% reduction (5-log orderreduction). These reductions can be evaluated using a procedure set outin Germicidal and Detergent Sanitizing Action of Disinfectants, OfficialMethods of Analysis of the Association of Official Analytical Chemists,paragraph 960.09 and applicable sections, 15th Edition, 1990 (EPAGuideline 91-2). According to this reference a sanitizer should providea 99.999% reduction (5-log order reduction) within 30 seconds at roomtemperature, 25±2° C., against several test organisms.

As used herein, the term “disinfectant” refers to an agent that killsall vegetative cells including most recognized pathogenicmicroorganisms, using the procedure described in A.O.A.C. Use DilutionMethods, Official Methods of Analysis of the Association of OfficialAnalytical Chemists, paragraph 955.14 and applicable sections, 15thEdition, 1990 (EPA Guideline 91-2). As used herein, the term “high leveldisinfection” or “high level disinfectant” refers to a compound orcomposition that kills substantially all organisms, except high levelsof bacterial spores, and is effected with a chemical germicide clearedfor marketing as a sterilant by the Food and Drug Administration. Asused herein, the term “intermediate-level disinfection” or “intermediatelevel disinfectant” refers to a compound or composition that killsmycobacteria, most viruses, and bacteria with a chemical germicideregistered as a tuberculocide by the Environmental Protection Agency(EPA). As used herein, the term “low-level disinfection” or “low leveldisinfectant” refers to a compound or composition that kills someviruses and bacteria with a chemical germicide registered as a hospitaldisinfectant by the EPA.

As used in this invention, the term “sporicide” refers to a physical orchemical agent or process having the ability to cause greater than a 90%reduction (1-log order reduction) in the population of spores ofBacillus cereus or Bacillus subtilis within 10 seconds at 60° C. Incertain embodiments, the sporicidal compositions of the inventionprovide greater than a 99% reduction (2-log order reduction), greaterthan a 99.99% reduction (4-log order reduction), or greater than a99.999% reduction (5-log order reduction) in such population within 10seconds at 60° C.

Differentiation of antimicrobial “-cidal” or “-static” activity, thedefinitions which describe the degree of efficacy, and the officiallaboratory protocols for measuring this efficacy are considerations forunderstanding the relevance of antimicrobial agents and compositions.Antimicrobial compositions can affect two kinds of microbial celldamage. The first is a lethal, irreversible action resulting in completemicrobial cell destruction or incapacitation. The second type of celldamage is reversible, such that if the organism is rendered free of theagent, it can again multiply. The former is termed microbiocidal and thelater, microbiostatic. A sanitizer and a disinfectant are, bydefinition, agents which provide antimicrobial or microbiocidalactivity. In contrast, a preservative is generally described as aninhibitor or microbiostatic composition

As used herein, the term “alkyl” or “alkyl groups” refers to saturatedhydrocarbons having one or more carbon atoms, including straight-chainalkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, nonyl, decyl, etc.), cyclic alkyl groups (or “cycloalkyl” or“alicyclic” or “carbocyclic” groups) (e.g., cyclopropyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, etc.), branched-chain alkyl groups(e.g., isopropyl, tert-butyl, sec-butyl, isobutyl, etc.), andalkyl-substituted alkyl groups (e.g., alkyl-substituted cycloalkylgroups and cycloalkyl-substituted alkyl groups).

Unless otherwise specified, the term “alkyl” includes both“unsubstituted alkyls” and “substituted alkyls.” As used herein, theterm “substituted alkyls” refers to alkyl groups having substituentsreplacing one or more hydrogens on one or more carbons of thehydrocarbon backbone. Such substituents may include, for example,alkenyl, alkynyl, halogeno, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy,alkoxycarbonyloxy, aryloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino),acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyland ureido), imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate,sulfates, alkylsulfinyl, sulfonates, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclic, alkylaryl, or aromatic(including heteroaromatic) groups.

In some embodiments, substituted alkyls can include a heterocyclicgroup. As used herein, the term “heterocyclic group” includes closedring structures analogous to carbocyclic groups in which one or more ofthe carbon atoms in the ring is an element other than carbon, forexample, nitrogen, sulfur or oxygen. Heterocyclic groups may besaturated or unsaturated. Exemplary heterocyclic groups include, but arenot limited to, aziridine, ethylene oxide (epoxides, oxiranes), thiirane(episulfides), dioxirane, azetidine, oxetane, thietane, dioxetane,dithietane, dithiete, azolidine, pyrrolidine, pyrroline, oxolane,dihydrofuran, and furan.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may include numbers thatare rounded to the nearest significant figure.

Weight percent, percent by weight, % by weight, wt %, and the like aresynonyms that refer to the concentration of a substance as the weight ofthat substance divided by the weight of the composition and multipliedby 100.

The recitation of numerical ranges by endpoints includes all numberssubsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4 and 5).

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. Thus, for example, reference to acomposition containing “a compound” includes a mixture of two or morecompounds. As used in this specification and the appended claims, theterm “or” is generally employed in its sense including “and/or” unlessthe content clearly dictates otherwise.

The use of the terms “antimicrobial” and “biocide” in this applicationdoes not mean that any resulting products are approved for use as anantimicrobial agent or biocide.

The compositions and methods disclosed herein may comprise, consist of,or consist essentially of the listed ingredients, or steps. As usedherein the term “consisting essentially of” refers to a composition ormethod that includes the disclosed ingredients or steps, and any otheringredients or steps that do not materially affect the novel and basiccharacteristics of the compositions or methods. For example,compositions that consist essentially of the listed ingredients do notcontain additional ingredients that would affect, for example, theantimicrobial or rheological properties of the compositions.

Compositions

The good detergency and broad biocidal efficacy of Generally Regarded AsSafe (GRAS) listed anionic surfactants make them ideal to be used asactive ingredients in a produce wash formula. However, the high foamprofile of these surfactants makes it hard for them to be used in aconvenient liquid form suitable for an automated dispensing system, suchas an Oasis Pro aspirator dispenser available from Ecolab. Dispensingsystems often generate large amounts of stable foam during thedispensing process from the concentrate form. The presence of foam isdetrimental when used in a no rinse formulation, e.g., a no rinseproduce wash formulation, as it not only impacts the visual appearanceof the contacted surface, but it can also change the taste, odor,texture and appearance of the contacted surface, e.g., produce.

As a result, it is preferred to eliminate the foam in formulas employingsuch ingredients. Incorporation of an appropriate defoamer into thecomposition is one approach to eliminate foam. Indeed, some commercialantimicrobial produce wash products employing anionic surfactant asactive ingredients do contain defoamer, such as silicon defoamer.However, these products are in the form of powder, making them mucheasier to formulate incorporating a defoamer. On the other hand, thesilicon defoamer poses significant technical challenges whenincorporated into a primarily aqueous liquid form, as these siliconparticles tend to aggregate in the composition, and cause phasestability issues.

In some aspects, the present disclosure relates to single phase,aqueous, low foaming antimicrobial compositions. The compositions arerheology modified such that they remain as a single phase in liquidform, and are low or no foaming, even when agitated, e.g., dispensedthrough an aspirator, or applied in an agitated bath, e.g., flumewaters. Further, the compositions do not need to be rinsed from thesurface they contact prior to consumption or use.

The compositions include at least an antimicrobial agent, an acidulant,a defoaming agent, and a thickening agent. The compositions furtherinclude at least about 25 wt % water. The compositions are phase stableliquid compositions. That is, they are not solids, e.g., powders,tablets, granules, etc. In some embodiments, the compositions do notinclude oxidizing agents, chlorites, or mixtures thereof. Nor do thecompositions include volatile solvents, e.g., monohydric alcoholvolatile solvents.

Antimicrobial Agents

In some aspects, the compositions include an antimicrobial agent. Insome embodiments, the antimicrobial agents suitable for use with thecompositions of the invention are GRAS antimicrobial agents or foodgrade compositions.

In some embodiments, the antimicrobial agent is selected from the groupconsisting of anionic surfactants, quaternary ammonium compounds andmixtures thereof. In some embodiments, the compositions can include morethan one antimicrobial agent. For example, in some embodiments, thecompositions can include one, two, three or four antimicrobial agents.

In some embodiments, the compositions include an anionic surfactant asan antimicrobial agent. The anionic surfactant can include, but is notlimited to, sulfates, sulfonates, and combinations thereof. Exemplaryanionic surfactants for use with the present compositions include alkylsulfates, alkyl sulfonates, alkyl aryl sulfonates, sulfonated fattyacids, sulfonated fatty acid esters, sulfonated carboxylic acid esters,and mixtures thereof. Sulfonated fatty acids suitable for use include,but are not limited to, sulfonated oleic acid, sulfonated linoleic acid,sulfonated palmitoleic acid and sulfonated stearic acid.

Additional exemplary antimicrobial agents include, but are not limitedto, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodiumdioctyl sulfosuccinate, sulfonated oleic acid, α-sulfonated carboxylicacid, dialkyl dimethyl ammonium chloride, alkylbenzyldimethyl ammoniumchloride and combinations thereof. In some embodiments, the compositionsare free or substantially free of a chlorite and/or an oxidizing agent.

In some embodiments, the compositions include between about 0.01 toabout 20 wt % of one or more antimicrobial agent, about 0.01 wt % toabout 10 wt % of one or more antimicrobial agent, or about 1.0 wt % toabout 5 wt % of one or more antimicrobial agent. It is to be understoodthat all values and ranges between these values and ranges are includedin the present disclosure.

Defoaming Agents

The compositions further include a defoaming agent. In some embodiments,the compositions can include defoamers which are of food grade quality.To this end, silicones can be used as effective defoaming agents. Thecompositions are designed such that silicones can be incorporated asdefoaming agents even though the compositions are in liquid form.Silicones such as dimethyl silicone, glycol polysiloxane, methylphenolpolysiloxane, trialkyl or tetralkyl silanes, hydrophobic silicadefoamers and mixtures thereof can all be used as defoamers in thecompositions. Commercial defoamers commonly available include siliconessuch as Ardefoam® from Armour Industrial Chemical Company which is asilicone bound in an organic emulsion; Foam Kill® or Kresseo® availablefrom Krusable Chemical Company which are silicone and non-silicone typedefoamers as well as silicone esters; and Anti-Foam A® and DC-200commercially available from Dow Corning Corporation. Other additionaldefoaming agents suitable for use with the compositions include, but arenot limited to, FG10, and 1520, commercially available from Dow CorningCorporation, and Hodag FD-82K, commercially available from Lambent. Adefoaming agent can be present at a concentration range from about 0.01wt % to 20 wt %, from about 0.1 wt % to 10 wt %, or from about 0.01 wt %to about 2 wt %. In some embodiments, the compositions include more thanzero but less than 1 wt % defoaming agent. It is to be understood thatall values and ranges between these values and ranges are incorporatedin the present disclosure.

Acidulants

In some embodiments, the compositions include an acidulant. Theacidulant can be present at an amount effective to form a concentratecomposition with pH of about 1 or less. In other embodiments, theacidulant can be present at an amount effective to form a usecomposition with pH of about 5, about 5 or less, about 4, about 4 orless, about 3, about 3 or less, about 2, about 2 or less, or the like.In some embodiments, the composition has a pH of between about 0 toabout 6, about 1 to about 5, or about 2 to about 4. In otherembodiments, the composition has a pH of less than about 3.2.

In some embodiments, the acidulant includes an inorganic acid. Suitableinorganic acids include, but are not limited to, sulfuric acid, sodiumbisulfate, phosphoric acid, nitric acid, hydrochloric acid, and mixturesthereof. In some embodiments, the acidulant includes an organic acid.Suitable organic acids include, but are not limited to, methane sulfonicacid, ethane sulfonic acid, propane sulfonic acid, butane sulfonic acid,xylene sulfonic acid, benzene sulfonic acid, formic acid, acetic acid,mono, di, or tri-halocarboyxlic acids, picolinic acid, dipicolinic acid,levulinic acid and mixtures thereof. In some embodiments, thecompositions of the present invention are free or substantially free ofa phosphorous based acid.

The compositions may also include a carboxylic acid. In someembodiments, the carboxylic acid includes, but is not limited to, analpha hydroxy carboxylic acid, sulfonated carboxylic acids, and mixturesthereof. As used herein, the term “alpha hydroxy carboxylic acid” refersto chemical compounds that include a carboxylic acid substituted with ahydroxyl group on the adjacent carbon. Alpha hydroxy carboxylic acidsinclude, for example, glycolic acid, lactic acid, malic acid, citricacid and tartaric acid.

In some embodiments, the carboxylic acid for use with the compositionsof the present invention includes a C1 to C22 carboxylic acid. In someembodiments, the carboxylic acid for use with the compositions is a C5to C11 carboxylic acid. In some embodiments, the carboxylic acid for usewith the compositions is a C1 to C4 carboxylic acid. Examples ofsuitable carboxylic acids include, but are not limited to, formic,acetic, propionic, butanoic, pentanoic, hexanoic, heptanoic, octanoic,nonanoic, decanoic, undecanoic, dodecanoic, as well as their branchedisomers, lactic, maleic, ascorbic, citric, hydroxyacetic, neopentanoic,neoheptanoic, neodecanoic, oxalic, malonic, succinic, glutaric, adipic,pimelic subric acid, and mixtures thereof. In some embodiments, thecomposition is substantially free, or free of a C5 to C11 carboxylicacid. In other embodiments, the composition is substantially free, orfree of a C1 to C4 carboxylic acid. In some embodiments, the compositionis substantially free, or free of both a C1 to C4 carboxylic acid, and aC5 to C11 carboxylic acid.

In some embodiments, the compositions include more than one acidulant.For example, in some embodiments, the compositions include one, two,three or four acidulants.

In some embodiments, the acidulant selected can also function as astabilizing agent. Thus, the compositions of the present invention canbe substantially free of an additional stabilizing agent.

In certain embodiments, the present composition includes about 0.5 toabout 80 wt-% acidulant, about 1 to about 50 wt %, about 5 to about 30wt-% acidulant, or about 10 wt % to about 30 wt-% acidulant. It is to beunderstood that all values and ranges between these values and rangesare encompassed by the compositions disclosed herein.

Stabilizing Agent

In some embodiments, the compositions also include a stabilizing agent.In some embodiments, the stabilizing agent is a food grade or GRASstabilizing agent. The stabilizing agents aid in maintaining stabilityof the compositions. For example, in some embodiments, the stabilizingagents aid in maintaining the stability of the compositions in hardwater. In some embodiments, the stabilizing agent is present at anamount effect to prevent the formation of a precipitate for at least 24hours when the composition is diluted with 500 ppm hard water.

Any of a variety of stabilizing agents can be used in the disclosedcompositions. In some embodiments, the stabilizing agent includes anethylene oxide/propylene oxide block copolymer, mixtures thereof, or thelike. In some embodiments, the copolymers have a molecular weight ofabout 5000 to about 10,000 and the percentage of ethylene oxide isbetween about 70 to about 90. Suitable ethylene oxide/propylene oxideblock copolymers include for example, those sold under the Pluronictradename (e.g., Pluronic F108 and Pluronic F68) and commerciallyavailable from BASF Corporation. Other exemplary stabilizers for use inthe present invention include nonionic surfactants and emulsifiers, forexample, polysorbate 80.

In some embodiments, one or more stabilizing agent may be present. Insome embodiments, the stabilizing agent is present at between about 0.1wt % and about 5.0 wt % of the composition. In other embodiments, thestabilizing agent is present between about 0.1 wt % and about 1.0 wt %.It is to be understood that all values and ranges between these valuesand ranges are encompassed by the present disclosure.

Thickening Agents

The compositions also include a thickening agent. The thickening agentsmay be food grade or GRAS. The thickening agents increase the viscosityof the compositions, and allow for the incorporation of a defoamingagent into the compositions under acidic conditions. That is, thethickening agent is present at an amount effective to maintain a phasestable composition when the defoaming agent is present.

In some embodiments, the thickening agent is selected from the groupconsisting of natural polysaccharide or cellulose thickeners, plantexudates, seaweed extracts, water soluble polymers, polyacrylic acidbased thickeners, polyacrylamide based thickeners, inorganic clay basedthickeners, and mixtures thereof. Natural polysaccharide or cellulosethickeners include, but are not limited to, guar gum, locust bean gum,xanthan gum, pectin, and gellan gum. Plant exudates include, but are notlimited to, acacia, ghatti, and tragacanth. Seaweed extracts include,but are not limited to, sodium alginate, and sodium carrageenan.Suitable polymers include, but are not limited to, hydroxyethylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcelluse, anddextrans.

In some embodiments, the composition has a viscosity of between about 50centipoise and about 3,500 centipoise when tested with spindle 3 at 50rpm on a Brookfield RVDVI+ viscometer, and the thickening agent ispresent in an amount effective such that the composition is phase stableunder acidic conditions. In other embodiments, the composition includesbetween about 0.1 wt % and about 10 wt % thickening agent. In otherembodiments, the composition includes less than about 1.0 wt % of athickening agent.

Carrier

In some embodiments, the compositions include a carrier. The carrierprovides a medium which dissolves, suspends, or carries the othercomponents of the composition. The carrier concentration and type willdepend upon the nature of the composition as a whole, the environmentalstorage, and method of application including concentration of theantimicrobial agent, among other factors. Notably the carrier should bechosen and used at a concentration which does not inhibit theantimicrobial efficacy of the active agent in the composition of theinvention. When used to wash a food contact surface, viz. produce, thecarrier selected should be one that would not adversely affect the foodcontact surface.

In some embodiments, the carrier includes water. In some embodiments,the carrier does not include volatile solvents. For example, in someembodiments, the compositions do not include volatile monohydric alcoholsolvents, including, but not limited to, aliphatic alcohols or a glycolether.

The carrier can be included in the compositions at a concentration of atleast about 25 wt %, at least 25 wt %, at least about 50 wt %, at least50 wt %, from about 20 wt % to about 90 wt %, or from about 40 wt % toabout 70 wt %. It is to be understood that all values and ranges betweenthese values and ranges are to be encompassed by the present disclosure.

Dye

In some embodiments, the compositions include one or more dyes. The dyescan be food grade or GRAS dyes. The dyes aid in providing evidence thatthe antimicrobial composition is present in the treatment solution,e.g., in the sink or wash water. The dyes for use with the compositionsmust be stable at a low pH, e.g., pH less than about 2. Dyes suitablefor use with the disclosed compositions include, but are not limited toFD&C Green 3, FD& C Yellow 5, and mixtures thereof.

If included, a dye is present at an amount effective to be visible whenthe composition is diluted to use level. In some embodiments, the dye ispresent at between about 0.0001 wt % and about 1.0 wt %, or betweenabout 0.001 wt % and about 0.01 wt %. It is to be understood that allvalues and ranges between these values and ranges are encompassed by thepresent disclosure.

Additional Ingredients

The compositions of the invention can include additional ingredients.The additional ingredients can include, but are not limited to, asurfactant, a processing aid, a colorant, an odorant, an anti-browningagent and mixtures thereof.

Use Compositions and Methods of Use Thereof

The compositions include concentrate compositions and use compositions.For example, a concentrate composition can be diluted, for example withwater, to form a use composition. In an embodiment, a concentratecomposition can be diluted to a use solution before to application to anobject. For reasons of economics, the concentrate can be marketed and anend user can dilute the concentrate with water or an aqueous diluent toa use solution. In other embodiments, a use composition can includeabout 0.01 to about 10 wt % of a concentrate composition and about 90 toabout 99.99 wt % diluent; or about 0.1 to about 2 wt % of a concentratecomposition and about 98 to about 99.9 wt-% diluent.

In some embodiments, the compositions are diluted with water. Thecompositions can be diluted at a ratio of between about 1:1 to about1:512. In other embodiments, the compositions can be diluted at a ratioof between about 1:64 to about 1:256. The dilution ratio can varydepending on the diluent being used.

In some aspects, the present disclosure includes methods of using thedisclosed antimicrobial compositions. For example, the methods include amethod for reducing a microbial population, a method for reducing thepopulation of a microorganism on skin, a method for treating a diseaseof skin, and/or a method for reducing an odor. These methods can operateon an article, surface, in a body or stream of water or a gas, or thelike, by contacting the article, surface, body, or stream with acomposition. Contacting can include any of numerous methods for applyingcomposition, such as spraying the compositions, immersing the article inthe compositions or a combination thereof.

In some aspects, the methods include a composition present at an amounteffective for killing one or more of the food-borne pathogenic bacteriaassociated with a food product, including, but not limited to,Salmonella typhimurium, Salmonella javiana, Salmonella enterica,Campylobacter jejuni, Listeria monocytogenes, and Escherichia coliO157:H7, yeast, and mold. In some embodiments, the methods includeapplying compositions at an amount effective for killing one or more ofthe pathogenic bacteria associated with a health care surfaces andenvironments including, but not limited to, Salmonella typhimurium,Staphylococcus aureus, methicilin resistant Staphylococcus aureus,Salmonella choleraesurus, Pseudomonas aeruginosa, Escherichia coli,mycobacteria, yeast, and mold. The compositions have activity against awide variety of microorganisms such as Gram positive (for example,Listeria monocytogenes or Staphylococcus aureus) and Gram negative (forexample, Escherichia coli or Pseudomonas aeruginosa) bacteria, yeast,molds, bacterial spores, viruses, etc. The compositions of the presentinvention, as described above, have activity against a wide variety ofhuman pathogens. The present compositions can kill a wide variety ofmicroorganisms on a food processing surface, on the surface of a foodproduct, in water used for washing or processing of food product, on ahealth care surface, or in a health care environment.

The compositions can be applied in a variety of areas includingkitchens, bathrooms, factories, hospitals, dental offices and foodplants, and can be applied to a variety of hard or soft surfaces havingsmooth, irregular or porous topography. Suitable hard surfaces include,for example, architectural surfaces (e.g., floors, walls, windows,sinks, tables, counters and signs); eating utensils; hard-surfacemedical or surgical instruments and devices; and hard-surface packaging.Such hard surfaces can be made from a variety of materials including,for example, ceramic, metal, glass, wood or hard plastic. Suitable softsurfaces include, for example paper; filter media; hospital and surgicallinens and garments; soft-surface medical or surgical instruments anddevices; and soft-surface packaging. Such soft surfaces can be made froma variety of materials including, for example, paper, fiber, woven ornonwoven fabric, soft plastics and elastomers. The compositions can alsobe applied to soft surfaces such as food and skin (e.g., a hand). Thecompositions can be included in products such as sterilants, sanitizers,disinfectants, preservatives, deodorizers, antiseptics, fungicides,germicides, sporicides, virucides, detergents, bleaches, hard surfacecleaners.

The compositions can also be used in veterinary products such asmammalian skin treatments or in products for sanitizing or disinfectinganimal enclosures, pens, watering stations, and veterinary treatmentareas such as inspection tables and operation rooms. The presentcompositions can be employed in an antimicrobial foot bath for livestockor people.

In some aspects, the compositions can be employed for reducing thepopulation of pathogenic microorganisms, such as pathogens of humans,animals, and the like. The compositions exhibit activity againstpathogens including fungi, molds, bacteria, spores, and viruses, forexample, S. aureus, E. coli, Streptococci, Legionella, Pseudomonasaeruginosa, mycobacteria, tuberculosis, phages, or the like. Suchpathogens can cause a variety of diseases and disorders, includingmastitis or other mammalian milking diseases, tuberculosis, and thelike. The compositions can reduce the population of microorganisms onskin or other external or mucosal surfaces of an animal. In addition,the present compositions can kill pathogenic microorganisms that spreadthrough transfer by water, air, or a surface substrate. The compositionsneed only be applied to the skin, other external or mucosal surfaces ofan animal water, air, or surface.

The antimicrobial compositions can also be used on foods and plantspecies to reduce surface microbial populations; used at manufacturingor processing sites handling such foods and plant species; or used totreat process waters around such sites. For example, the compositionscan be used on food transport lines (e.g., as belt sprays); boot andhand-wash dip-pans; food storage facilities; anti-spoilage aircirculation systems; refrigeration and cooler equipment; beveragechillers and warmers, blanchers, cutting boards, third sink areas, andmeat chillers or scalding devices. The compositions can be used to treatproduce transport waters such as those found in flumes, pipe transports,cutters, slicers, blanchers, retort systems, washers, and the like.Particular foodstuffs that can be treated with compositions of theinvention include eggs, meats, seeds, leaves, fruits and vegetables.Particular plant surfaces include both harvested and growing leaves,roots, seeds, skins or shells, stems, stalks, tubers, corms, fruit, andthe like. The compositions may also be used to treat animal carcasses toreduce both pathogenic and non-pathogenic microbial levels.

The compositions can also be employed by dipping food processingequipment into the use solution, soaking the equipment for a timesufficient to sanitize the equipment, and wiping or draining excesssolution off the equipment, The compositions may be further employed byspraying or wiping food processing surfaces with the use solution,keeping the surfaces wet for a time sufficient to sanitize the surfaces,and removing excess solution by wiping, draining vertically, vacuuming,etc.

The compositions may also be used in a method of sanitizing hardsurfaces such as institutional type equipment, utensils, dishes, healthcare equipment or tools, and other hard surfaces. The antimicrobialcompositions can be applied to microbes or to soiled or cleaned surfacesusing a variety of methods. These methods can operate on an object,surface, in a body or stream of water or a gas, or the like, bycontacting the object, surface, body, or stream with a compound of theinvention. Contacting can include any of numerous methods for applying acompound, such as spraying the compound, immersing the object in thecompound, or a combination thereof.

A concentrate or use concentration of a composition can be applied to orbrought into contact with an object by any conventional method orapparatus for applying an antimicrobial or cleaning compound to anobject. For example, the object can be wiped with, sprayed with, foamedon, and/or immersed in the compound, or a use solution made from thecomposition. The composition can be sprayed, foamed, or wiped onto asurface; the composition can be caused to flow over the surface, or thesurface can be dipped into the composition. Contacting can be manual orby machine.

Methods for Contacting a Food Product

In some aspects, the present disclosure provides methods for contactinga food product with an antimicrobial composition employing any method orapparatus suitable for applying such a composition. Contacting the foodproduct can occur in any location in which the food product might befound, such as field, processing site or plant, vehicle, warehouse,store, restaurant, or home. These same methods can also be adapted toapply the compositions to other objects.

The present methods require a certain minimal contact time of thecomposition with food product for occurrence of significantantimicrobial effect. The contact time can vary with concentration ofthe use composition, method of applying the use composition, temperatureof the use composition, amount of soil on the food product, number ofmicroorganisms on the food product, type of antimicrobial agent, or thelike. The exposure time can be at least about 5 to about 15 seconds. Insome embodiments, the exposure time is about 15 to about 30 seconds. Inother embodiments, the exposure time is at least about 30 seconds. Instill yet other embodiments, the exposure time is about one minute,about two minutes, or about four minutes.

In other embodiments, the exposure time is the amount of time it takesfor the composition to dry on the contacted surface. For example thetreated surface may be exposed to the compositions for about 20 to about60 minutes, or about 30 to about 45 minutes.

In some embodiments, the method for washing a food product employs apressure spray including the disclosed compositions. During applicationof the spray solution on the food product, the surface of the foodproduct can be moved with mechanical action, e.g., agitated, rubbed,brushed, etc. Agitation can be by physical scrubbing of the foodproduct, through the action of the spray solution under pressure,through sonication, or by other methods. In some embodiments, theagitation occurs in a sink, e.g., a PowerSoak® sink. Agitation increasesthe efficacy of the spray solution in killing micro-organisms, perhapsdue to better exposure of the solution into the crevasses or smallcolonies containing the micro-organisms. Further, the compositions areformulated such that despite high agitation, they remain low to nofoaming.

The spray solution, before application, can also be heated to atemperature of about 15 to 20° C., for example, about 20 to 60° C. toincrease efficacy. The spray stabilized composition can be left on thefood product for a sufficient amount of time to suitably reduce thepopulation of microorganisms, and then rinsed, drained, or evaporatedoff the food product.

Application of the material by spray can be accomplished using a manualspray wand application, an automatic spray of food product moving alonga production line using multiple spray heads to ensure complete contact,or other spray apparatus. One automatic spray application involves theuse of a spray booth. The spray booth substantially confines the sprayedcompound to within the booth. The production line moves the food productthrough the entryway into the spray booth in which the food product issprayed on all its exterior surfaces with sprays within the booth. Aftera complete coverage of the material and drainage of the material fromthe food product within the booth, the food product can then exit thebooth. The spray booth can include steam jets that can be used to applythe stabilized compositions of the invention. These steam jets can beused in combination with cooling water to ensure that the treatmentreaching the food product surface is less than 65° C., e.g., less than60° C. The temperature of the spray on the food product is important toensure that the food product is not substantially altered (cooked) bythe temperature of the spray. The spray pattern can be virtually anyuseful spray pattern.

Immersing a food product in a liquid composition can be accomplished byany of a variety of methods known to those of skill in the art. Forexample, the food product can be placed into a tank or bath containingthe stabilized composition. Alternatively, the food product can betransported or processed in a flume of the stabilized composition. Thewashing solution can be agitated to increase the efficacy of thesolution and the speed at which the solution reduces micro-organismsaccompanying the food product. Agitation can be obtained by conventionalmethods, including ultrasonics, aeration by bubbling air through thesolution, by mechanical methods, such as strainers, paddles, brushes,pump driven liquid jets, or by combinations of these methods. Thewashing solution can be heated to increase the efficacy of the solutionin killing micro-organisms. After the food product has been immersed fora time sufficient for the desired antimicrobial effect, the food productcan be removed from the bath or flume and the stabilized composition canbe rinsed, drained, or evaporated off the food product.

The following examples are provided for the purpose of illustration, notlimitation.

EXAMPLES Example 1

A test was performed to evaluate the impact of the addition of adefoaming agent to an exemplary produce wash formulation. Threeformulations were tested. Compositions A and B were prepared inaccordance with embodiments of the present disclosure. Compositions Aand B are shown in the table below.

Agent Composition A Composition B Anionic Surfactant 6.84 6.84 C5-C11Carboxylic 1.00 1.00 Acid Defoaming Agent 0.50 0.00 Lactic Acid 19.6519.65 Thickening Agent 0.40 0.40 Processing Aid 1.20 1.20 StabilizingAgent 0.64 0.64 Miscellaneous 0.055 0.055 DI Water To 100 To 100Composition A also included a defoaming agent. Composition B includedthe same antimicrobial composition as included in Composition A, but didnot include a defoaming agent. Comparative Composition 1 included acommercially available produce wash, Fit® Fruit and Produce Wash,commercially available from HealthPro Brands, Inc.

Each composition was diluted to a ratio of 1 ounce of produce wash to 1gallon of water (5 grain). Then 40 milliliters (mL) of each of thediluted solutions was added to a 250 mL graduated cylinder. The sampleswere then spun on a foam test machine for 4 minutes. The samples wereremoved from the machine and the foam height was immediately recorded.The graduated cylinders were also immediately photographed. The changein foam height after two minutes was also measured. The test was thenrepeated 2 more times. The results from this test are shown in the tablebelow.

TABLE 1 Foam Height (mL) Time = 10 Time = 120 Composition Replicateseconds seconds Composition A 1 0 0 2 0 0 3 0 0 Composition B 1 71 66 276 71 3 71 66 Comparative 1 21 16 Composition 1 2 26 16 3 21 16

As can be seen from these results, Composition A, which included adefoamer, had no foam present at either time point tested. CompositionB, which included the same produce wash as Composition A, but did notinclude a defoamer had a very high and very stable foam. Thecommercially available composition tested, Comparative Composition 1also formed a stable foam, however, it was not as high as the foamformed from Composition B. Overall, it was shown that the presence of adefoamer was important for reducing the foam height and stability incompositions in accordance with embodiments of the present invention.

Example 2

A study using Compositions A and B, as described above in Example 1, wasrun to evaluate the carryover of residual chemistry onto lettuce as afunction of the foam level and the concentration of various producewashes in accordance with the present invention.

For this study, Dole brand cut and prepackaged romaine lettuce heartswere used. The lettuce was weighed and placed in a strainer and thevessel was filled with six liters (L) of either Composition A or B. Thecompositions were dispensed into the vessel using an Oasis® CleaningSystem, commercially available from Ecolab Inc. The dispense time was 35seconds, at a flow rate of approximately 10.3 liters/minute.

Thirty seconds after the composition was applied, a picture was taken ofthe foam and the strainer was removed from the liquid. The strainer wasallowed to drain for 30 seconds and another photo was taken to visuallydocument the amount of foam present. The lettuce was then transferred byhand to a plastic zip-lock bag, and weighed. The initial weight of thebag was 11.6 grams.

This procedure was repeated using varying sized dispenser aspirator tipsto change the composition concentration, and the produce usage andresidual carryover weights were recorded. The results from this studyare shown in the table below and in FIG. 1.

TABLE 2 Weight percent of Liquid Antifoam Composition retained onResidual Sample (Y/N) (wt %) lettuce (g) chemistry (g) Composition B  1N  0.78% 26.85 0.21  2 N  1.81% 27.18 0.49  3 N  4.05% 27.91 1.13  4 N 6.39% 34.16 2.18  5 N 10.15% 48.74 4.95 Composition A  6 Y  0.86% 18.7 0.16  7 Y  1.81% 20.01 0.36  8 Y  4.15% 19.47 0.81  9 Y  6.88% 21.371.47 10 Y 10.50% 22.65 2.38

The results indicate that compositions that generate foam during washingor processing can carryover significantly more liquid/foam and residualchemistry than compositions that do not generate significant amounts offoam. The inclusion of antifoam to Composition A resulted in minimalfoam generation and much less carryover of residual chemistry than thecontrol Composition B prepared without an antifoaming agent.

Example 3

A study was performed to measure the ability of an antimicrobial producewash composition in accordance with embodiments of the presentdisclosure to reduce Listeria monocytogenes, Escherichia coli O157:H7and Salmonella enterica in processing waters for fruit and vegetables.The formula of the produce wash is also shown in the table below.

TABLE 3 Produce Wash Composition Amount (weight %) DI Water 67.95Anionic Surfactant 1.37 Combination of 26.32 Acidulants StabilizingAgent 3.06 Thickening Agent 0.70 Defoaming agent 0.60

The produce wash composition was tested against three different testsystems. Test System 1 included a Listeria monocytogenes mixture thatincluded: L. monocytogenes ATCC 49594, L. monocytogenes ATCC 19114, andL. monocytogenes ATCC 19116. Test System 2 included a Escherichia coliO157:H7 mixture that included E. coli O157:H7 ATCC 43895, E. coliO157:H7 ATCC 35150, and E. coli O157:H7 ATCC 43890. Test System 3included a Salmonella enterica mixture that included S. enterica subsp.enterica ATCC 10721, S. enterica subsp. enterica ATCC 6962, and S.enterica subsp. enterica ATCC 13311.

For this study, the produce wash was diluted to various concentrationsusing varying diluents, as shown in the table below.

TABLE 4 Desired Test Solution (Volume of Test Test SubstanceConcentration Diluent Substance/Total Volume) pH Produce Wash 1:171 405ppm Synthetic Hard 4.68 g/800.02 g 2.82 1:143 Water (pH 7.90) 5.59g/800.06 g 2.74 Produce Wash 1:256 410 ppm Synthetic Hard 2.0 g/500 g3.07 Water (pH 7.89) Produce Wash 1:256 200 ppm Synthetic Hard 3.9g/1000 g 3.12 Water (pH 7.89) 400 ppm Synthetic Hard 3.10 Water (pH7.89) Produce Wash 1:128 Sterile MilliQ Water 1.17 g/300 g 2.77 1:192(DI Water) 1.56 g/300 g 2.67 1:256 2.34 g/300 g 2.55 1:128 210 ppmSynthetic Hard 1.17 g/300 g 3.18 1:192 Water (pH 7.95) 1.56 g/300 g 2.941:256 2.34 g/300 g 2.72 1:128 420 ppm Synthetic Hard 1.17 g/300 g 3.031:192 Water (pH 7.91) 1.56 g/300 g 2.87 1:256 2.34 g/300 g 2.67 ProduceWash 1:200 200 ppm Synthetic Hard  3.5 g/700 g 2.95 1:220 Water (pH7.85) 3.18 g/700 g 2.95 1:200 410ppm Synthetic Hard  3.5 g/700 g 3.031:220 Water (pH 7.83) 3.18 g/700 g 3.01

For this study, 99 mL of the selected test substance (produce washdilution) was dispensed into a sterile 250 mL Erlenmeyer flask.Duplicate flasks with 99 mL of sterile phosphate buffered dilution water(PBDW) were also prepared for determination of the inoculum populations.The test flasks were vigorously swirled. While the liquid in the flaskwas still in motion, the tip of a pipette containing 1 mL of theselected Test System suspension was immersed in the test substancemidway between the center and the edge of the flask. One (1) mL of theTest System suspension was dispensed into 99 mL of the test substance(produce wash dilution).

After the selected exposure time, 1 mL of the test substance mixture wastransferred into 9 mL of an inactivating agent using a sterile pipetteand vortex to mix. This tube was considered to contain a 10⁻¹ dilutionof the test solution. For the test substance use solution test samples,1 mL and 0.1 mL from the 10⁻¹ inactivating agent tube were plated. Forthe inoculum population tests, a 10⁻⁵ and a 10⁻¹ dilution in PBDW wereprepared. 1 mL and 0.1 mL from these dilutions were plated. The plateswere inverted and allowed to incubate at 35±2° C. for 48±4 hours. Theresults from this study are shown in the tables below.

TABLE 5 Inoculum Numbers Average Log₁₀ Log₁₀ Test System CFU/mL GrowthGrowth Listeria monocytogenes 118 × 10⁶, 121 × 10⁶ 8.07, 8.08 8.08mixture Escherichia coli O157:H7 141 × 10⁶, 146 × 10⁶ 8.15, 8.04 8.10mixture Salmonella enterica mixture 116 × 10⁶, 102 × 10⁶ 8.06, 8.01 8.04

TABLE 6 Listeria monocytogenes Mixture Average Log Test ExposureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:171 in 90 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.08 400 ppm120 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.08 hard water 1:143 in 90sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.08 400 ppm 120 sec 0 × 10¹, 0× 10¹ <1.00, <1.00 <1.00 >7.08 hard water

TABLE 7 Escherichia coli O157:H7 Mixture Average Log Test ExposureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:171 in 90 sec 1 × 10¹, 4 × 10¹ 1.00, 1.60 1.30 6.80 400 ppm 120sec 2 × 10¹, 1 × 10¹ 1.30, 1.00 1.15 6.95 hard water 1:143 in 90 sec 0 ×10¹, 0 × 10¹ <1.00, <1.00 >7.10 400 ppm <1.00 hard water 120 sec 0 ×10¹, 0 × 10¹ <1.00, <1.00 >7.10 <1.00 * E. coli O157:H7 ATCC 43895appeared contaminated before testing, so was not included in themixture.

TABLE 8 Salmonella enterica Mixture Average Log Test Exposure SurvivorsLog₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivors tion1:171 in 90 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 400 ppm 120sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 hard water 1:143 in 90 sec1 × 10¹, 0 × 10¹ 1.00, <1.00 <1.00 >7.04 400 ppm 120 sec 0 × 10¹, 0 ×10¹ <1.00, <1.00 <1.00 >7.04 hard water

TABLE 9 Inoculum Numbers Average Log₁₀ Log₁₀ Test System CFU/mL GrowthGrowth Listeria monocytogenes 134 × 10⁶, 110 × 10⁶ 8.13, 8.04 8.09mixture Escherichia coli O157:H7 125 × 10⁶, 127 × 10⁶ 8.10, 8.10 8.10mixture Salmonella enterica mixture 147 × 10⁶, 148 × 10⁶ 8.17, 8.17 8.17

TABLE 10 Listeria monocytogenes Mixture Average Log Test ExposureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:256 in  90 sec 0 × 10¹ <1.00 <1.00 >7.09 400 ppm 120 sec 0 × 10¹<1.00 <1.00 >7.09 hard water

TABLE 11 Escherichia coli O157:H7 Mixture Average Log Test ExposureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:256 in  90 sec 585 × 10³ 5.77 5.77 2.33 400 ppm 120 sec 176 × 10³5.25 5.25 2.85 hard water

TABLE 12 Salmonella enterica Mixture Average Log Test Exposure SurvivorsLog₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivors tion1:256 in  90 sec  74 × 10³ 4.87 4.87 3.30 400 ppm 120 sec 306 × 10¹ 3.493.49 4.68 hard water

TABLE 13 Inoculum Numbers Average Log₁₀ Log₁₀ Test System CFU/mL GrowthGrowth Listeria monocytogenes 99 × 10⁶, 105 × 10⁶ 7.99, 8.02 8.01mixture Escherichia coli O157:H7 92 × 10⁶, 92 × 10⁶ 7.96, 7.96 7.96mixture Salmonella enterica mixture 104 × 10⁶, 126 × 10⁶ 8.02, 8.10 8.06

TABLE 14 Listeria monocytogenes Mixture Test Exposure Survivors Log₁₀Average Log₁₀ Log Substance Time (CFU/mL) Survivors Survivors Reduction1:256 in 60 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.01 200 ppm 90 sec0 × 10¹, 124 × 10¹ <1.00, 3.09 2.05 5.96 hard water 120 sec 0 × 10¹, 0 ×10¹ <1.00, <1.00 <1.00 >7.01 5 min 0 × 10¹, 0 × 10¹ <1.00, <1.00<1.00 >7.01 10 min 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.01 1:256 in 5min 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.01 400 ppm 10 min 0 × 10¹, 0× 10¹ <1.00, <1.00 <1.00 >7.01 hard water

TABLE 15 Escherichia coli O157:H7 Mixture Test Exposure Survivors Log₁₀Average Log₁₀ Log Substance Time (CFU/mL) Survivors Survivors Reduction1:256 in 60 sec 328 × 10⁵, 316 × 10⁵ 7.51, 7.50 7.51 0.45 200 ppm 90 sec194 × 10⁵, 212 × 10⁵ 7.29, 7.33 7.31 0.65 hard water 120 sec 106 × 10⁵,124 × 10⁵ 7.03, 7.09 7.06 0.90 5 min 134 × 10³, 178 × 10³ 5.13, 5.255.19 2.77 10 min 47 × 10¹, 108 × 10¹ 2.67, 3.03 2.85 5.11 1:256 in 5 min341 × 10¹, 369 × 10¹ 3.53, 3.57 3.55 4.41 400 ppm 10 min 2 × 10¹, 3 ×10¹ 1.30, 1.48 1.39 6.57 hard water

TABLE 16 Salmonella enterica Mixture Test Exposure Survivors Log₁₀Average Log₁₀ Log Substance Time (CFU/mL) Survivors Survivors Reduction1:256 in 60 sec 258 × 10⁵, 227 × 10⁵ 7.41, 7.36 7.39 0.67 200 ppm 90 sec79 × 10⁵, 81 × 10⁵ 6.90, 6.91 6.91 1.15 hard water 120 sec 24 × 10⁵, 19× 10⁵ 6.38, 6.28 6.33 1.73 5 min 209 × 10¹, 25 × 10¹ 3.32, 2.40 2.865.20 10 min 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.06 1:256 in 5 min 0 ×10¹, 4 × 10¹ <1.00, 1.60 1.30 6.76 400 ppm 10 min 0 × 10¹, 0 × 10¹<1.00, <1.00 <1.00 >7.06 hard water

TABLE 17 Inoculum Numbers Average Log₁₀ Log₁₀ Test System CFU/mL GrowthGrowth Escherichia coli O157:H7 80 × 10⁶, 110 × 10⁶ 7.90, 8.04 7.97mixture

TABLE 18 Escherichia coli O157:H7 Mixture Test Exposure Survivors Log₁₀Average Log₁₀ Log Substance Time (CFU/mL) Survivors Survivors Reduction1:256 in 90 sec 5 × 10¹, 7 × 10¹ 1.70, 1.84 1.77 6.20 DI water 1:256 in218 × 10⁵, 212 × 10⁵ 7.34, 7.33 7.34 0.63 200 ppm HW 1:256 in 46 × 10⁵,45 × 10⁵ 6.66, 6.65 6.66 1.31 400 ppm HW 1:192 in 0 × 10¹, 1 × 10¹<1.00, 1.00 <1.00 >6.97 DI water 1:192 in 20 × 10¹, 8 × 10¹ 2.30, 1.902.10 5.87 200 ppm HW 1:192 in 40 × 10¹, 18 × 10¹ 2.60, 2.26 2.43 5.54400 ppm HW 1:128 in 1 × 10¹, 0 × 10¹ 1.00, <1.00 <1.00 >6.97 DI water1:128 in 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >6.97 200 ppm HW 1:128 in 0× 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >6.97 400 ppm HW

TABLE 19 Inoculum Numbers Average Log₁₀ Log₁₀ Test System CFU/mL GrowthGrowth Listeria monocytogenes 108 × 10⁶, 113 × 10⁶ 8.03, 8.05 8.04mixture Escherichia coli O157:H7 94 × 10⁶, 130 × 10⁶ 7.97, 8.11 8.04mixture Salmonella enterica mixture 183 × 10⁶, 183 × 10⁶ 8.26, 8.26 8.26

TABLE 20 Listeria monocytogenes Mixture Expo- Average Log Test sureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:200 in  90 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 200 ppm120 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 hard water 1:200 in 90 sec 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 400 ppm 120 sec 0 ×10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 hard water 1:220 in  90 sec 0 ×10¹, 0 × 10¹ <1.00, <1.00 <1.00 >7.04 200 ppm 120 sec 0 × 10¹, 0 × 10¹<1.00, <1.00 <1.00 >7.04 hard water 1:220 in  90 sec 10 × 10¹, 10 × 10¹2.00, 2.00 2.00 6.04 400 ppm 120 sec 74 × 10¹, 12 × 10¹ 2.87, 2.08 2.475.57 hard water

TABLE 21 Escherichia coli O157:H7 Mixture Expo- Average Log Test sureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Survivors Survivorstion 1:200 in  90 sec 183 × 10³, 72 × 10³  5.26, 4.86 5.06 2.98 200 ppm120 sec 9 × 10³, 4 × 10³ 3.95, 3.60 3.78 4.26 hard water 1:200 in  90sec 58 × 10³, 71 × 10³ 4.76, 4.85 4.81 3.24 400 ppm 120 sec  4 × 10³,276 × 10¹ 3.60, 3.44 3.52 4.52 hard water 1:220 in  90 sec 11 × 10⁵, 15× 10⁵ 6.04, 6.18 6.11 1.93 200 ppm 120 sec 323 × 10³, 185 × 10⁵ 5.51,5.27 5.39 2.66 hard water 1:220 in  90 sec 13 × 10⁵, 17 × 10⁵ 6.11, 6.236.17 1.87 400 ppm 120 sec 240 × 10³, 6 × 10⁵  5.38, 5.78 5.58 2.46 hardwater

TABLE 22 Salmonella enterica Mixture Expo- Log₁₀ Average Log Test sureSurvivors Sur- Log₁₀ Reduc- Substance Time (CFU/mL) vivors Survivorstion 1:200 in  90 sec 1 × 10¹, 0 × 10¹ 1.00, <1.00 >7.26 200 ppm <1.00hard water 120 sec 0 × 10¹, 6 × 10¹ <1.00, 1.39 6.87 1.78 1:200 in  90sec 1 × 10¹, 5 × 10¹ 1.00, 1.35 6.91 400 ppm 1.70 hard water 120 sec 0 ×10¹, 0 × 10¹ <1.00, <1.00 >7.26 <1.00 1:220 in  90 sec 230 × 10¹, 178 ×10¹ 3.36, 3.31 4.96 200 ppm 3.25 hard water 120 sec 1 × 10¹, 0 × 10¹1.00, <1.00 7.26 <1.00 1:220 in  90 sec 15 × 10³, 7 × 10³  4.18, 4.014.25 400 ppm 3.84 hard water 120 sec 31 × 10¹, 40 × 10¹ 2.49, 2.55 5.722.60

The results are also summarized in the tables below.

TABLE 23 Listeria monocytogenes Produce Wash in 200 ppm Hard Water LogReduction Dilution 60 sec 90 sec 120 sec 5 min 10 min 1:256 >7.015.96 >7.01 >7.01 >7.01 1:220 >7.04 >7.04 1:200 >7.04 >7.04 1:128 ProduceWash in 400 ppm Hard Water Log Reduction Dilution 90 sec 120 sec 5 min10 min 1:256 >7.09 >7.09 >7.01 >7.01 1:220 6.04 5.57 1:200 >7.04 >7.041:171 >7.08 >7.08 1:143 >7.08 >7.08 1:128

TABLE 24 Escherichia coli O157:H7 Produce Wash in DI Water Log ReductionDilution 90 sec 1:256 6.20 1:192 >6.97 1:128 >6.97 Produce Wash in 200ppm Hard Water Log Reduction Dilution 60 sec 90 sec 120 sec 5 min 10 min1:256 0.45 0.65/0.63 0.90 2.77 5.11 1:220 1.93 2.66 1:200 2.98 4.261:192 5.54/5.87 1:128 >6.97 Produce Wash in 400 ppm Hard Water LogReduction Dilution 90 sec 120 sec 5 min 10 min 1:256 2.33/1.31 2.85 4.416.57 1:220 1.87 2.46 1:200 3.24 4.52 1:192 5.54 1:171 6.80 6.951:143 >7.10 >7.10 1:128 >6.97

TABLE 25 Salmonella enterica Produce Wash in 200 ppm Hard Water LogReduction Dilution 60 sec 90 sec 120 sec 5 min 10 min 1:256 0.67 1.151.73 5.20 >7.06 1:220 4.96 7.26 1:200 >7.26 6.87 1:128 Produce Wash in400 ppm Hard Water Log Reduction Dilution 90 sec 120 sec 5 min 10 min1:256 3.30 4.68 6.76 >7.06 1:220 4.25 5.72 1:200 6.91 >7.261:171 >7.04 >7.04 1:143 >7.04 >7.04 1:128

As can be seen from these results, the exemplary formulations testedachieved significant antimicrobial performance at multipleconcentrations in the wash water solution. Antimicrobial reductionsachieved will reduce cross contamination that could occur during thewashing of produce and maintain a sterile wash basin for additional foodprocessing. In some applications in which extended contact times areallowed, the exemplary formulations tested showed expanded antimicrobialperformance over tested performance intervals at the full range ofconcentrations tested.

Example 4

A study was performed to evaluate the residual efficacy of an exemplaryproduce wash composition in accordance with embodiments of the presentdisclosure to reduce Listeria monocytogenes, Escherichia coli O157:H7and Salmonella enterica on the surface of spinach leaves. The followingproduce wash composition was used for this study:

TABLE 26 Produce Wash Composition Amount (weight %) DI Water 67.95Anionic Surfactant 1.37 Combination of 26.32 Acidulants StabilizingAgent 3.06 Thickening Agent 0.70 Defoaming agent 0.60

For this study, pre-washed spinach leaves were purchased from a localgrocery store. The leaves were sorted, and those that were broken orlooked damaged were discarded. Five leaves per treatment and controlwere picked. The leaves were placed spine side down on a rack. Each leafwas inoculated with 8-10 spots, equaling a total of 100 μL of prepared10⁻⁸ Colony forming units (CFU)/mL of Test System culture. The followingTest Systems were used: Test System 1 included a Listeria monocytogenesmixture that included L. monocytogenes ATCC 49594, L. monocytogenes ATCC19114, and L. monocytogenes ATCC 19116. Test System 2 included anEscherichia coli O157:H7 mixture that included E. coli O157:H7 ATCC43895, E. coli O157:H7 ATCC 35150, and E. coli O157:H7 ATCC 43890.

After the leaves were inoculated, they were dried at room temperaturefor 45 minutes, or until the inoculum was visibly dry. Then, 300 mL ofthe test substance (diluted produce wash) was dispensed into a 600 mLbeaker. The test substance dilutions used in this study are shown below.

TABLE 27 Test Solution Desired (Volume of Test Concentration DiluentSubstance/Total Volume) pH 0.75 oz/gal 380 ppm Synthetic 10.4 g/1951.4 gn/a Hard Water (pH 7.71) 0.75 oz/gal 400 ppm Synthetic 10.4 g/2000.0 g2.98 Hard Water (pH 7.71)

Samples were exposed to the bulk test substance for 90 seconds thenremoved and allowed a dwell time equal to sample times listed in table29 below, viz., pre-exposure, immediately post exposure, 2 minutespost-exposure, 5 minutes post-exposure, 10 minutes post-exposure, 15minutes post-exposure, and 30 minutes post-exposure. At the end of thedesired evaluation time, extended activity profile was measured postneutralization vs. an equivalent water control at each time point.Extended activity is a measurement of cumulative kill independent ofreduction observed in bulk solution.

The results from this study are shown in the tables below.

TABLE 28 Inoculum Numbers Test System CFU/mL Log₁₀ Growth Average Log₁₀Growth Listeria monocytogenes 73 × 10⁶, 7.86, 7.91 7.89 mixture 81 × 10⁶

TABLE 29 Listeria monocytogenes Mixture Avg. Log₁₀ Log Sample TimeSurvivors (CFU/Surface) Log₁₀ Growth Growth Reduction Pre-exposure 1.00× 10⁶, 2.20 × 10⁶, 1.40 × 10⁶, 6.00, 6.34, 6.15, 6.15 N/A 8.00 × 10⁵,2.40 × 10⁶ 5.90, 6.38 Immediately 1.88 × 10³, 2.40 × 10², 1.60 × 10²,3.27, 2.38, 2.20, 2.34 3.81 Post-exposure <2.00 × 10¹, 4.20 × 10² <1.30,2.62  2 minutes 8.80 × 10², 2.32 × 10³, 4.00 × 10¹, 2.94, 3.37, 1.60,2.43 3.72 Post-exposure 2.20 × 10², 8.00 × 10¹ 2.34, 1.90  5 minutes8.00 × 10¹, 8.00 × 10¹, 1.20 × 10⁴, 1.90, 1.90, 4.08, 2.34 3.81Post-exposure 1.60 × 10², 4.00 × 10¹ 2.20, 1.60 10 minutes 4.40 × 10⁴,8.60 × 10², <2.00 × 10¹, 4.64, 2.93, <1.30, 2.75 3.40 Post-exposure 3.62× 10³, <2.00 × 10¹ 2.56, <1.30 15 minutes <2.00 × 10¹, <2.00 × 10¹, 3.00× 10², <1.30, <1.30, 2.48, 1.54 4.61 Post-exposure <2.00 × 10¹, <2.00 ×10¹ <1.30, <1.30 30 minutes 2.00 × 10², 1.00 × 10², <2.00 × 10¹, 2.30,2.00, <1.30, 1.64 4.51 Post-exposure 2.00 × 10¹, <2.00 × 10¹ 1.30, <1.30

TABLE 30 Inoculum Numbers Log₁₀ Average Test System CFU/mL Growth Log₁₀Growth Escherichia coli 176 × 10⁶, 201 × 10⁶ 8.25, 8.30 8.27 O157:H7mixture

TABLE 31 Escherichia coli O157:H7 Mixture Avg. Log₁₀ Log Sample TimeSurvivors (CFU/Surface) Log₁₀ Growth Growth Reduction Pre-exposure 1.62× 10⁵, 1.34 × 10⁵, 1.04 × 10⁵, 5.21, 5.13, 5.02, 5.16 N/A 1.48 × 10⁵,1.88 × 10⁵ 5.17, 5.27 Immediately 6.00 × 10³, 2.00 × 10³, 2.00 × 10³,3.78, 3.30, 3.30, 3.75 1.41 Post-exposure 5.00 × 10⁴, 4.82 × 10³ 4.70,3.68  2 minutes 1.80 × 10⁴, 1.40 × 10⁴, 4.00 × 10³, 4.25, 4.15, 3.60,4.06 1.10 Post-exposure 1.20 × 10⁴, 1.60 × 10⁴ 4.08, 4.20  5 minutes6.00 × 10³, 1.04 × 10³, 9.60 × 10², 3.78, 3.02, 2.98, 3.14 2.02Post-exposure 1.20 × 10³, 7.20 × 10² 3.08, 2.86 10 minutes 1.00 × 10²,<2.00 × 10¹, 2.04 × 10³, 2.00, <1.30, 3.31, 2.24 2.92 Post-exposure 4.80× 10², 8.00 × 10¹ 2.68, 1.90 15 minutes <2.00 × 10¹, 8.00 × 10¹, 1.28 ×10³, <1.30, 1.90, 3.11, 1.84 3.32 Post-exposure <2.00 × 10¹, 4.00 × 10¹1.30, 1.60 30 minutes 2.00 × 10¹, 4.00 × 10¹, <2.00 × 10¹, 1.30, 1.60,<1.30, 1.92 3.24 Post-exposure 8.80 × 10², 3.00 × 10² 2.94, 2.48

As can be seen from these results, the exemplary produce washcomposition carried over on the surface of the treated materialsachieved expanded kill performance for at least 45 minutes post bulksolution exposure. This expanded kill on the surface of produce enhancesfood safety benefits to the formulation and falls within many fieldapplications.

Example 6

A study was performed to compare the effect of different acids onexemplary antimicrobial produce wash compositions. For this study,lactic acid, and sodium acid sulfate (SAS) were used. The produce washcompositions tested are shown in the table below.

TABLE 32 Formula A (Lactic Acid) Formula B (SAS) Raw Material Amt (g)Raw Material Amt (g) Anionic Surfactant 0.64 Anionic Surfactant 0.64Acidulant 0.50 Acidulant 1.50 Defoaming Agent 0.25 Defoaming Agent 0.25Lactic Acid, 88% 8.92 Sodium Bisulfate 2.65 Thickener 0.75 Thickener0.75 Stabilizing Agent 2.57 Stabilizing Agent 2.57 Grapefruit Oil 0.05Grapefruit Oil 0.05 DI Water 86.32 DI Water 91.59 Total 100.00 Total100.00 pH after dilution 3.12 pH after dilution 3.04

Both Formula A and Formula B were diluted at 1:64 ratio in 205 ppmsynthetic hard water, and were tested against Escherichia coli ATCC11229 at 1 and 2 minute exposure times. For this study, 99 mL of theselected test substance (Formula A or B diluted) was dispensed into asterile 250 mL Erlenmeyer flask. Duplicate flasks with 99 mL of sterilephosphate buffered dilution water (PBDW) were also prepared fordetermination of the inoculum populations. The test flasks werevigorously swirled. While the liquid in the flask was still in motion,the tip of a pipette containing 1 mL of the selected Test Systemsuspension was immersed in the test substance midway between the centerand the edge of the flask. One (1) mL of the Test System suspension wasdispensed into 99 mL of the test substance (Formula A or B diluted).There was also a 10% vegetable soil in the hard water.

After the selected exposure time, 1 mL of the test substance mixture wastransferred into 9 mL of an inactivating agent using a sterile pipetteand vortex to mix. This tube was considered to contain a 10⁻¹ dilutionof the test solution. For the test substance use solution test samples,1 mL and 0.1 mL from the 10⁻¹ inactivating agent tube were plated. Forthe inoculum population tests, a 10⁻⁵ and a 10⁻¹ dilution in PBDW wereprepared. 1 mL and 0.1 mL from these dilutions were plated. The plateswere inverted and allowed to incubate at 35±2° C. for 48±4 hours. Theresults from this study are shown in the tables below.

TABLE 33 Inoculum Numbers Log₁₀ Average Test System CFU/mL Growth Log₁₀Growth Escherichia coli ATCC 11229 78 × 10⁶ 7.89 7.89 77 × 10⁶ 7.89

TABLE 34 Escherichia coli ATCC 11229 Expo- Average Log Test sureSurvivors Log₁₀ Log₁₀ Reduc- Substance Time (CFU/mL) Growth Growth tionFormula A 1 min 110 × 10¹, 44 × 10¹  3.04, 2.64 2.84 5.05 (Lactic Acid)2 min 0 × 10¹, 0 × 10¹ <1.00, <1.00 <1.00 >6.89 Formula B 1 min 68 ×10³, 66 × 10³ 4.83, 4.82 4.82 3.07 (SAS) 2 min 123 × 10¹, 29 × 10³ 3.09, 4.46 3.78 4.11

As can be seen from these results, Formula A which contained lactic acidhad about a 5 log reduction after only 1 minute. Formula B whichcontained SAS only had about a 3 log reduction after 1 minute. Thus,Formula A passed with greater than the recommended 4 log reduction after1 minute and 2 minutes, against E. coli. Formula B (the SAS producewash) only passed with greater than a 4 log reduction after 2 minutes,against E. coli. Overall, it was found that the lactic acid produce washperformed better than the SAS produce wash.

The foregoing summary, detailed description, and examples provide asound basis for understanding the disclosure, and some specific exampleembodiments of the disclosure. Since the disclosure can comprise avariety of embodiments, the above information is not intended to belimiting. The invention resides in the claims.

We claim:
 1. A method for reducing a population of microorganisms on asurface comprising: (a) providing a single phase aqueous low foamingantimicrobial concentrate composition comprising: (i) at least about 25wt % water; (ii) an antimicrobial agent comprising an anionicsurfactant; (iii) a defoaming agent; (iv) an acidulant selected from thegroup consisting of sulfates, sulfonates, and combinations thereof; (v)a stabilizing agent; and (vi) a thickening agent, wherein thecomposition has a viscosity of between about 50 centipoise and about3500 centipoise, and the thickening agent is present in an amounteffective such that the composition is phase stable under acidicconditions; (b) diluting the composition; and (c) contacting the surfacewith the diluted composition such that the population of microorganismsis reduced, wherein the composition does not need to be rinsed from thesurface.
 2. The method of claim 1, wherein the anionic surfactant isselected from the group consisting of alkyl sulfates, alkyl sulfonates,alkyl aryl sulfonates, sulfonated fatty acids, sulfonated fatty acidesters, sulfonated carboxylic acid esters, and mixtures thereof.
 3. Themethod of claim 1, wherein the defoaming agent comprises a siliconedefoaming agent.
 4. The method of claim 1, wherein the thickening agentis selected from the group consisting of natural polysaccharide orcellulose thickeners, plant exudates, seaweed extracts, water solublepolymers, poly acrylic acid based thickeners, polyacrylamide basedthickeners, inorganic clay based thickeners, and mixtures thereof. 5.The method of claim 1, wherein the acidulant comprises a food additiveingredient.
 6. The method of claim 1, wherein the acidulant is selectedfrom the group consisting of lactic acid, citric acid, sodium bisulfate,acetic acid, adipic acid, tartaric acid, propionic acid, malic acid,lactic acid, sulfuric acid, and derivatives and mixtures thereof.
 7. Themethod of claim 1, wherein the composition comprises: between about 0.01wt % and about 50 wt % of the antimicrobial agent; between about 0.01 wt% and about 10.0 wt % defoaming agent; between about 0.1 wt % and about10 wt % thickening agent; and between about 1 wt % to about 50 wt % ofthe acidulant.
 8. The method of claim 1, wherein the composition isdiluted at about a 1:64 to about a 1:128 ratio.
 9. The method of claim1, wherein the composition is phase stable for at least about one yearat a temperature of about
 25. degrees C.
 10. The method of claim 1,wherein the microorganism is selected from the group consisting ofspores, bacteria, mold, yeast, viruses, and combinations thereof. 11.The method of claim 1, wherein the step of contacting reduces thepopulation of the microorganism by at least about 4 log reduction after1 minute.
 12. The method of claim 1, wherein the surface comprisesproduce selected from the group consisting of fruits, vegetables andmixtures thereof.
 13. The method of claim 1, wherein the surfacecomprises a food contact surface.
 14. The method of claim 1, wherein thefood contact surface comprises a food processing tool selected from thegroup consisting of utensils, trays, strainers, cutting boards,dishware, pots, pans, and combinations thereof.
 15. A method for washingproduce comprising: (a) contacting the produce with a phase stableaqueous acidic antimicrobial composition comprising: (i) at least about25 wt % water; (ii) an antimicrobial agent comprising an anionicsurfactant; (iii) a defoaming agent; (iv) an acidulant; (v) astabilizing agent; and (vi) a thickening agent present in an amounteffective such that the composition is phase stable under acidicconditions, wherein the composition is diluted prior to contacting andhas a viscosity of between about 50 centipoise and about 3500centipoise, and the produce does not need to be rinsed after beingcontacted by the composition.
 16. The method of claim 15, wherein thecomposition does not substantially affect the organoleptic properties ofthe produce after contacting the produce.
 17. The method of claim 15,wherein the step of contacting comprises placing the produce in anagitated bath containing a water source and the composition.
 18. Themethod of claim 15, wherein the step of contacting comprises dilutingthe composition through an aspirator and spraying it on to a surface ofthe produce.
 19. The method of claim 15, wherein after the step ofcontacting the composition remains on the surface of the produce forbetween about 30 to about 60 minutes prior to drying.
 20. The method ofclaim 19, wherein the composition reduces the population of themicroorganism on the surface by about 4 log after remaining on thesurface for between about 30 and about 60 minutes.